Foremost among the improvements for me is the introduction of several new chart libraries, one of which I want to focus on here.
The Calendar View provides an ingenious way to show datasets that would typically be displayed in a line chart, due to the sheer volume of data points. The d3 calendar view helps us display daily data by year, month, and day, while simultaneously displaying results in a weekly grid. In addition, the color coding provides a quick and intuitive way to see patterns in the data. Here's an example, from the d3 site:
The d3 example is built using stock market data, but the same approach can be used for any daily results – in a baseball context, this could be runs scored by game, winning (or losing) margin in each game, or even the number of pitches thrown per game by the starting pitcher.
I'll look at some of the other d3 libraries soon, and begin incorporating them into the Collections page on the site.